The present invention relates to an improved lamp socket for the reception of a lamp used as an automotive brake light, head light, parking light, turn signal and the like. In addition, the improved lamp socket has numerous uses and applications outside the automobile industry.
The lamp sockets used in automobiles and other vehicles today generally comprise a socket housing adapted to be securely fastened in a light fixture, a central core member positioned in the socket housing, a light bulb releasably secured in the socket housing, and at least one wire connected to the terminals of the core member. The wire leads to the wiring harness of the vehicle. The core member has one or more relatively movable metal contacts for mating with the contacts on the end of the light bulb. These contacts often consist of tubular members which are inserted in complimentary holes in the core member. A spring may be positioned around each of the tubular members to provide the requisite "lost motion" to maintain contact pressure between the bulb and core contacts.
Conventional lamp sockets are generally assembled by inserting the core member into the socket from the bulb-accepting end thereof. In most instances, wires are soldered or otherwise connected to the tubular members of the core members. The wires generally must be fed through the socket housing. The socket housings are then secured in place in the light fixtures in the vehicle.
Such known lamp sockets have numerous disadvantages. The core members consist of separate contacts creating unnecessary expense in both materials and assembly. The core member contacts provide a wipe-and-slide contact with the contacts on the bulbs which does not always clean the oxidation from the contacts and often results in a poor or unworkable electrical connection.
The present invention overcomes the aforementioned disadvantages. The core member of the improved lamp socket comprises one or more sections which, when assembled, are generally cylindrical in shape. Where a two-sectioned core member is provided, the sections fit together to form the cylindrical shape. The core member has at least one channel or passageway formed in to accept and fixedly secure at least one spade terminal in the core member. The core member is inserted into the socket housing from the bulb end thereof, locking tabs maintaining it in place. A spring is positioned around the core member to provide the needed "lost motion" with a bulb.
After the core member is fixed in the socket housing and the housing is secured in position in the light fixture, the appropriate wires from the wire harness are simply inserted into place in the core member. More specifically, spade terminals on the wire are merely inserted into complimentary slots in the core member from the end opposite from the bulb-accepting end of the housing. Tabs in the slots retain terminals securely in place. A light bulb is then positioned in the socket housing in the conventional manner, (lugs being accepted by J-shaped grooves).
The spade terminals have edge-like ends for making electrical contact with the contacts on the end of a light bulb. When a bulb is inserted into the sockets, (pushed down hard, turned slightly, and then released), the terminals make a wiping and cutting contact with the bulk contacts. This insures a good contact as the cutting action slices through whatever oxidation and film might exist on the bulb contacts.
Where the core member has two sections, each section may be made of a different color to insure mating with the proper wires in a wiring harness. Also, the two-sectioned core member permits relative movement between the sections to allow the spade terminals to make proper contact with uneven bulb terminals. Rear assembly of the wires is possible. Further, the present invention eliminates one element in the electrical circuit between the bulb and the wires in the wire harness and thus reduces the milivolt drop from the bulb to the wires.
The present invention can be used with either single or double contact bulbs. If the light fixture only utilizes a single contact bulb, a one-piece core member is utilized. Many of the features and advantages of the present invention are realized in this embodiment.
Further features and advantages of the present invention will become apparent from the following description, claims and drawings.